OBSERVATIONS ON THE PHAGOCYTOSIS OF THE PNEUMOCOCCUS BY HUMAN WHOLE BLOOD : I. THE NORMAL PHAGOCYTIC TITRE, AND THE ANTI-PHAGOCYTIC EFFECT OF THE SPECIFIC SOLUBLE SUBSTANCE.

1. The phagocytic titre of whole human blood against the three types of pneumococcus was determined in a number of individuals. The titre varied over a considerable range in different subjects. 2. Contrary to expectation, the titre in early cases of untreated pneumonia was quite high against the infecting organism, pointing to a local rather than a general lowering of resistance in infection with this organism. 3. Sia's work was confirmed, that the specific carbohydrate has a specific anti-phagocytic action on the blood. This action is more marked in the case of Type III than in Type I.